test.kt

package tigaer.inventory

import android.Manifest
import android.annotation.SuppressLint
import android.app.Activity
import android.content.Context
import android.content.DialogInterface
import android.content.Intent
import android.content.pm.PackageManager
import android.database.Cursor
import android.graphics.Bitmap
import android.os.AsyncTask
import android.os.Build
import android.os.Bundle
import android.provider.MediaStore
import android.support.v4.app.ActivityCompat
import android.support.v4.content.ContextCompat
import android.support.v7.app.AlertDialog
import android.support.v7.app.AppCompatActivity
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.BaseAdapter
import android.widget.Button
import android.widget.CheckBox
import android.widget.GridView
import android.widget.ImageView
import kotlinx.android.synthetic.main.custom_gallery.*

/**
 * Created by User on 06/11/2017.
 */
class CustomPhotoGalleryActivity : AppCompatActivity() {

    private var grdImages: GridView? = null
    private var btnSelect: Button? = null

    private val imageAdapter: ImageAdapter? = null
    private var arrPath: Array<Any> = emptyArray()
    private val thumbnailsselection: BooleanArray? = null
    private val ids: IntArray? = null
    private var count: Int = 0

    private val MY_PERMISSIONS_REQUEST_READ_CONTACTS = 1

    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)
        setContentView(R.layout.custom_gallery)

        // Here, thisActivity is the current activity
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {

            // Should we show an explanation?
            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.READ_EXTERNAL_STORAGE)) {

                // Show an explanation to the user *asynchronously* -- don't block
                // this thread waiting for the user's response! After the user
                // sees the explanation, try again to request the permission.

            } else {

                // No explanation needed, we can request the permission.

                ActivityCompat.requestPermissions(this,
                        arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE),
                        MY_PERMISSIONS_REQUEST_READ_CONTACTS)

                // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
                // app-defined int constant. The callback method gets the
                // result of the request.

                val builder: AlertDialog.Builder
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                    builder = AlertDialog.Builder(this, android.R.style.Theme_Material_Dialog_Alert)
                } else {
                    builder = AlertDialog.Builder(this)
                }

            }

        }

        grdImages = findViewById<View>(R.id.grdImages) as GridView
        btnSelect = findViewById<View>(R.id.btnSelect) as Button

        val columns = arrayOf(MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID)
        val orderBy = MediaStore.Images.Media._ID
        val imagecursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null, null, orderBy)
        val image_column_index = imagecursor.getColumnIndex(MediaStore.Images.Media._ID)
        this.count = imagecursor.getCount()

//        arrPath = Array<Any>?(this.count)
        val ids = IntArray(count)
//        thumbnailsselection = BooleanArray(this.count)
        for (i in 0 until this.count) {
            imagecursor.moveToPosition(i)
            ids[i] = imagecursor.getInt(image_column_index)
            val dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA)
            arrPath[i] = imagecursor.getString(dataColumnIndex)
        }

        val imageAdapter = ImageAdapter()
        grdImages!!.adapter = imageAdapter
        imagecursor.close()
    }


    /**
     * This method used to set bitmap.
     *
     * @param iv represented ImageView
     * @param id represented id
     */

    private fun setBitmap(iv: ImageView?, id: Int) {

        object : AsyncTask<Void, Void, Bitmap>() {

            override fun doInBackground(vararg params: Void): Bitmap {
                return MediaStore.Images.Thumbnails.getThumbnail(applicationContext.contentResolver, id.toLong(), MediaStore.Images.Thumbnails.MICRO_KIND, null)
            }

            override fun onPostExecute(result: Bitmap) {
                super.onPostExecute(result)
                iv!!.setImageBitmap(result)
            }
        }.execute()
    }


    inner class ImageAdapter : BaseAdapter() {
        private val mInflater: LayoutInflater

        init {
            mInflater = getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
        }

        override fun getCount(): Int {
            return count
        }

        override fun getItem(position: Int): Any {
            return position
        }

        override fun getItemId(position: Int): Long {
            return position.toLong()
        }

        override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
            var convertView = convertView
            val holder: ViewHolder
            if (convertView == null) {
                holder = ViewHolder()
                convertView = mInflater.inflate(R.layout.custom_gallery_item, null)
                holder.imgThumb = convertView!!.findViewById<View>(R.id.imgThumb) as ImageView
                holder.chkImage = convertView.findViewById<View>(R.id.chkImage) as CheckBox

                convertView.tag = holder
            } else {
                holder = convertView.tag as ViewHolder
            }
            holder.chkImage!!.id = position
            holder.imgThumb!!.id = position
            holder.chkImage!!.setOnClickListener { v ->
                val cb = v as CheckBox
                val id = cb.id
                if (thumbnailsselection!![id]) {
                    cb.isChecked = false
                    thumbnailsselection[id] = false
                } else {
                    cb.isChecked = true
                    thumbnailsselection[id] = true
                }
            }
            holder.imgThumb!!.setOnClickListener {
                val id = holder.chkImage!!.id
                if (thumbnailsselection!![id]) {
                    holder.chkImage!!.isChecked = false
                    thumbnailsselection[id] = false
                } else {
                    holder.chkImage!!.isChecked = true
                    thumbnailsselection[id] = true
                }
            }
            try {
                setBitmap(holder.imgThumb, ids!![position])
            } catch (e: Throwable) {
            }

            holder.chkImage!!.isChecked = thumbnailsselection!![position]
            holder.id = position
            return convertView
        }
    }

    /**
     * Inner class
     *
     * @author tasol
     */
    internal inner class ViewHolder {
        var imgThumb: ImageView? = null
        var chkImage: CheckBox? = null
        var id: Int = 0
    }

    companion object {

        private val MY_PERMISSIONS_REQUEST_READ_CONTACTS = 1
    }

}